<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Title</title>
</head>
<body>
<script>
    setTimeout(()=>{
        console.log(1)
    },0)

    new Promise((resolve)=>{
        console.log(2)
        resolve()
    }).then(()=>{
        console.log(3)
    }).then(()=>{
        console.log(4)
    })
    console.log(5)

    // 同步：[2,5]
    // 宏：[1]
    // 微：[3,4]
</script>
</body>
</html>
